1. Field of the Invention
The present invention relates to electrical connectors and more particularly to plastic strips for use in manufacturing insulative housings for use in electrical connectors.
2. Brief Description of Prior Developments
It has been suggested that the use of pin header connectors in continuous reel form might be desirable due to lower costs of assembly and inventory. By obtaining headers in strip form and using automated assembly equipment to cut parts to length and place, a manufacturer might be able to significantly reduce inventory requirements. Furthermore, component to circuit board assembly throughput rate might also be improved.
The prior art, for example U.S. Pat. No. 4,832,622 to Zahn, teaches the use of continuous extrusion plastic strips for producing insulative plastic strips for use in manufacturing unshrouded housings for electrical headers. One drawback, however, to the continuous extrusion of plastic strips for this purpose is that secondary operations may be required to produce the full finished part configuration. For example, it may be necessary to cut lateral notches to serve as points for segmenting the strip into individual insulative plastic strips. It may also be necessary to perforate the strip to provide apertures for the placement of pins or other conductive members in the completed connectors.
The aforesaid Zahn patent also suggests that a continuous plastic strip may be manufactured in discrete segments by injection molding. In one proposed mode of manufacturing a continuous plastic strip by injection molding, Zahn teaches the use of a separate longitudinal spline as a carrier for the units to be molded. A disadvantage to this approach may, however, be that the use of the separate longitudinal spline may contribute to the complexity and expense of the overall operation. In another proposed mode, Zahn teaches the sequential molding of discrete units in series without a separate spline. Since, however, no specific means may be disclosed for interlocking the sequentially molded segments, the resulting continuously molded strip may lack the degree of flexibility or strength that would be desirable for certain uses such as being capable of being wound on a reel to extended lengths.
A need, therefore, exists for a continuous plastic strip which can be used as or to manufacture an electrical connector housing which does not require expensive finishing operations. A need also exists for such a continuous plastic strip which may be manufactured without a separate longitudinal spline or carrier. A still further need exists for a continuous plastic strip which has the necessary strength and flexibility that would enable it to be wound on a reel at extended lengths to facilitate its subsequent transport and storage.